Conventionally, various types of pressure sensors are proposed for detecting a pressure that is transmitted from a diaphragm to a sensing portion of a sensor element by a pressure transmission member that is interposed between the diaphragm and the sensing portion of the sensor element. For example, U.S. Pat. No. 5,488,868 discloses a pressure sensor for generating a detection signal upon detecting a pressure of an object with the above-described structure that includes the diaphragm that warps under pressure of the object, the sensor element, and the pressure transmission member that touches one surface of the diaphragm by one end and also touches the sensing portion of the sensor element by another end.
However, the diaphragm in the pressure sensor is always pressed by the pressure transmission member for securely having contact with the transmission member. Therefore, the diaphragm is prone to damage such as breakage caused by the pressure from the pressure transmission member. In this case, the thickness of the diaphragm may be increased for improved mechanical strength of the diaphragm, with the sensitivity of the pressure sensor being compromised in return for the improved strength.